Momentum and Impulse

Front

Linear Momentum Noun

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[lin-ee-er moh-men-tuhm]

Back

Linear Momentum

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The product of an object's mass and its velocity, representing the quantity of motion an object has in a straight line.

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Example: This diagram shows a moving block hitting a stationary one. By comparing the 'Before' and 'After' states, it illustrates the conservation of linear momentum.

Front

Mass Noun

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[mas]

Back

Mass

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A measure of the amount of matter in an object and its inherent resistance to acceleration, also known as inertia.

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Example: This diagram shows that mass (m) is a scalar quantity that relates the force (F) applied to an object and its resulting acceleration (a).

Front

Velocity Noun

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[vuh-los-i-tee]

Back

Velocity

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A vector quantity specifying the rate of change of an object's position, indicating both its speed and direction of motion.

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Example: This image shows a car moving at a specific speed (20 m.p.h.) in a specific direction (left), which together define its velocity.

Front

Frame of Reference Noun

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[freym uhv ref-er-uhns]

Back

Frame of Reference

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A coordinate system or set of axes used to measure and describe the motion and properties of objects.

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Example: An observer on the ground (C) sees the cart moving, but from a frame of reference inside the cart, points A and B are stationary.

Front

Vector Noun

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[vek-ter]

Back

Vector

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A physical quantity, such as velocity or force, that is defined by having both a magnitude and a direction.

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Example: Forces, like the pull on the box and friction, are shown as arrows. These arrows are vectors because they have both a direction and a magnitude (strength).

Front

Total Momentum Noun

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[toh-tl moh-men-tuhm]

Back

Total Momentum

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The vector sum of the individual momenta of all the objects that are contained within a defined system.

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Example: This diagram shows that the total momentum of a system of objects, like these two balls, remains the same before and after they collide.

Front

Center of Mass Noun

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[sen-ter uhv mas]

Back

Center of Mass

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The unique point in an object or system where the weighted average of all mass is considered to be concentrated.

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Example: This diagram shows the center of mass (C) for a system of two objects (m1 and m2), which is the average position of all the mass in the system.

Front

Impulse Noun

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[im-puhls]

Back

Impulse

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The change in an object's momentum, calculated as the product of the average force and the time it is applied.

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Example: When the car suddenly stops, the box on top continues to move forward due to its momentum, illustrating the effect of impulse and inertia.

Front

Inertia Noun

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[in-ur-shuh]

Back

Inertia

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The property of an object to resist any change in its state of motion, whether at rest or moving linearly.

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Example: A ball at rest stays at rest until kicked, and a ball in motion stays in motion until stopped by the net, demonstrating inertia.

Front

Moment of Inertia Noun

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[moh-muhnt uhv in-ur-shuh]

Back

Moment of Inertia

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An object's resistance to changes in its rotational motion, depending on its mass and how that mass is distributed.

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Example: An ice skater spins faster when she pulls her arms in because this reduces her moment of inertia, which is her resistance to rotational change.